Legendary Titans

These must be the legendary Titans. 

In the Hoenn Region, 

Regirock, Regice and Registeel were 3 Titans, 

in the Sinnoh Region, 

Regigigas was 1 Titan, 

and in the Galar Region, 

Regieleki and Regidraco were 2 Titans. 

Regirock, Regice, Registeel, Regigigas, Regieleki, and Regidraco 

were legendary Titans and legendary Pokémon. 

I bet Regidraco looks like a Golem with Dragon Jaws as its Arms.